diff --git a/pkgs/development/libraries/haskell/ad/default.nix b/pkgs/development/libraries/haskell/ad/default.nix
index 39c17de2c313..d53d11385f4d 100644
--- a/pkgs/development/libraries/haskell/ad/default.nix
+++ b/pkgs/development/libraries/haskell/ad/default.nix
@@ -1,3 +1,5 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
 { cabal, comonad, dataReify, doctest, erf, filepath, free, mtl
 , nats, reflection, tagged, transformers
 }:
diff --git a/pkgs/development/libraries/haskell/dom-selector/default.nix b/pkgs/development/libraries/haskell/dom-selector/default.nix
index 789eb354b310..b9806ca4dc7b 100644
--- a/pkgs/development/libraries/haskell/dom-selector/default.nix
+++ b/pkgs/development/libraries/haskell/dom-selector/default.nix
@@ -1,3 +1,5 @@
+# This file was auto-generated by cabal2nix. Please do NOT edit manually!
+
 { cabal, blazeHtml, htmlConduit, parsec, QuickCheck, text, thLift
 , xmlConduit
 }: